Enhancement of Heat Transfer in the Leading Edge of Gas Turbine Blade with Various Rib Turbulators

This study investigated heat transfer characteristics and improvement in a triangular channel with a rounded leading edge and rib turbulator. The channel cross section has a 120 degrees fillet on the leading edge of the equilateral triangle. The Reynolds number based on hydraulic diameter is 30,000. The angles of the rib turbulator are 45 degrees and 90 degrees. The rib height to hydraulic diameter ratio is 0.079 and the rib pitch to height ratio is 8. In a triangular channel with a large curvature of leading edge, the changing pressure field caused by the rib turbulator accelerates the flow and increases heat transfer. The 90 degrees rib showed higher heat transfer than 45 degrees rib on the leading edge region. To further improve the heat transfer, the effect of a pin added between the ribs and rib length extension was studied. As a result, the thermal performance factor was enhanced by 4 % and 9 %, respectively.